(19)

(11)

EP 1 611 314 A1

(12)

(43) Date of publication: 04.01.2006 Bulletin 2006/01 (21) Application number: 04724465.2 (22) Date of filing: 30.03.2004

(51) International Patent Classification (IPC):  E21B 43/20(1968.09) (86) International application number: PCT/NO2004/000091 (87) International publication number: WO 2004/090284 (21.10.2004 Gazette 2004/43)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR Designated Extension States: AL LT LV MK (30) Priority: 08.04.2003 NO 20031569 (71) Applicant: Sorco AS 4068 Stavanger (NO)	(72) Inventor: PINCHIN, Dave N-4085 Hundvag (NO) (74) Representative: Liebetanz, Michael  Isler & Pedrazzini AG Postfach 6940 8023 Zürich 8023 Zürich (CH)